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CN-121988981-A - Processing technology of tungsten carbide wedge-shaped riving knife large-depth-diameter ratio through hole

CN121988981ACN 121988981 ACN121988981 ACN 121988981ACN-121988981-A

Abstract

The invention relates to a processing technology of a through hole with a large depth-diameter ratio of a tungsten carbide wedge-shaped chopper, which comprises the following steps of sequentially adopting a vacuum powder mixing process, a cold isostatic pressing process and a vacuum sintering process to prepare a blank, adopting a red skin second laser to process and synchronously spraying electrolyte to a processing area, realizing composite rough processing, adopting a micro CT (computed tomography) device to detect deflection data of a through hole, adopting a low-power laser to carry out fixed-point laser correction on the deflection area according to the detection data, adopting an electrolytic processing mode to polish the inner wall of the through hole so as to remove melt remained in the laser processing, adopting a diamond microfilament honing head to carry out honing finishing on the micro scratches remained on the inner wall of the through hole, and adopting the red skin second laser to match with the electrolyte to carry out synchronous composite rough processing, realizing synchronous processing and deslagging, and fundamentally solving the problem of blockage of the deep hole melt, so that micropores with the ultra-large depth-diameter ratio of more than 100 are efficiently and stably formed.

Inventors

  • ZHOU LI
  • HUANG YUXUAN
  • Jiang Huanyan
  • LIU YELIN
  • LIU YAN
  • ZHOU ZIMING

Assignees

  • 湖南科芯精工科技有限公司

Dates

Publication Date
20260508
Application Date
20251211

Claims (10)

  1. 1. The processing technology of the tungsten carbide wedge-shaped riving knife large in depth-diameter ratio through hole is characterized by comprising the following steps of: S1, preparing a blank, namely sequentially adopting a vacuum powder mixing, cold isostatic pressing and vacuum sintering process to prepare a tungsten carbide hard alloy blank with high compactness and uniform components; S2, compound rough machining, namely clamping the blank body on a rotatable clamp, enabling the axis of the blank body to be coaxial with a laser light path, adopting an infrared skin second laser to align a designated machining area to etch away materials, machining in a layered spiral feeding mode to form a through hole, and synchronously spraying electrolyte to the machining area while laser machining, wherein the electrolyte is subjected to chemical reaction with a melt generated by the action of laser and is removed; s3, laser correction, namely detecting the deflection data of the pre-through hole by using a micro CT device, accurately transferring the blank to a laser correction device, and carrying out fixed point correction on the deflection area of the through hole by adopting low-power laser according to the detection data; S4, electrolytic finishing, namely polishing the inner wall of the through hole in an electrolytic machining mode to remove melt remained by laser machining; S5, honing finishing, namely clamping and fixing the blank body subjected to electrolytic finishing treatment, and honing the blank body in a reciprocating manner along the axial direction of the through hole by adopting a diamond microfilament honing head so as to eliminate micro scratches remained on the inner wall of the through hole after electrolysis; And S6, detecting the finished product, namely detecting the aperture, roughness and straightness of the through hole, and obtaining the finished product of the tungsten carbide wedge-shaped riving knife after qualification.
  2. 2. The process for machining the through hole with the large depth-to-diameter ratio of the tungsten carbide wedge chopper according to claim 1, wherein in the step S1, the specific steps for preparing the blank are as follows: S11, mixing powder, namely selecting superfine WC powder and Co powder, mixing according to the proportion of 90-92wt% of WC powder and 8-10wt% of Co powder, putting into a vacuum planetary mixer, mixing for 2-3 hours at the rotating speed of 30r/min, wherein the vacuum degree in the mixing process is less than 10 -2 Pa, avoiding powder oxidation and ensuring uniform components; s12, cold isostatic pressing, namely filling the powder mixed in the step S11 into a nitrile rubber mold, and pressing into a cylindrical blank body by isostatic pressing equipment under the pressure of 200-220MPa for 30min; s13, vacuum sintering, namely placing the blank formed in the step S12 into a vacuum sintering furnace, heating to 1450-1480 ℃ at a temperature rising rate of 5 ℃ per minute, preserving heat for 3-4 hours, and cooling along with the furnace to obtain a tungsten carbide blank with uniform components and high density.
  3. 3. The process for machining a through hole with a large depth-to-diameter ratio by using a tungsten carbide wedge-shaped chopper as claimed in claim 1, wherein in the step S2, the specific steps of the composite rough machining are as follows: S21, setting laser parameters, namely setting parameters of an infrared skin second laser, wherein the parameters comprise the wavelength of 1064nm, the pulse width of 10-50ps, the single pulse energy of 50-100 mu J, the repetition frequency of 2kHz and the diameter of a focusing light spot of 60-70 mu m; s22, preparing electrolyte, namely mixing 5wt% of sodium tungstate, 3wt% of hydrogen peroxide and the balance of deionized water to prepare the electrolyte, adjusting pH=8-9, spraying the electrolyte to a processing area through a coaxial spray head, wherein the spraying pressure is 15-20MPa, and the flow is 2-2.5L/min; S23, layering spiral machining, namely starting a blank body to rotate, axially feeding a laser head for red skin seconds, scanning a laser spot of a laser beam for red skin seconds along the circumference of a hole wall for one circle every time a certain depth is machined, axially pushing an action position of the laser on the hole wall for a certain distance every circle, forming a continuous spiral machining track, ensuring that the hole wall in the depth direction of the whole through hole is uniformly eroded by the laser, stopping machining when the laser head is axially fed to the depth of the target through hole in a cumulative mode, and finishing through hole forming.
  4. 4. The process for machining a through hole with a large depth-to-diameter ratio by using a tungsten carbide wedge chopper according to claim 3, wherein in the step S23, the rotating speed of the blank body is 150-200r/min, the axial feeding speed of a laser head is 2-4mm/h, each time a depth of 50 μm is machined, a laser spot of a laser beam of a red skin second sweeps a circle along the circumference of a hole wall, and the axial feeding amount of two adjacent circumferential sweeps is 10-15 μm.
  5. 5. The process for machining a through hole with a large depth-to-diameter ratio by using a tungsten carbide wedge chopper as claimed in claim 1, wherein in the step S3, the specific steps of laser correction are as follows: S31, micro CT detection, namely clamping the blank processed in the step S2 on a clamp with a standard positioning reference, acquiring pre-through hole deflection data through micro CT detection, detecting that the straightness of the through hole is less than or equal to 0.05mm, and if the straightness of the through hole is less than or equal to 0.05mm, entering the step S32, otherwise, returning to the step S23; s32, laser fixed-point correction, namely transferring the blank body subjected to the micro CT detection to a clamp of laser correction equipment and fixing, wherein the positioning reference of the clamp is consistent with that of the clamp used by the micro CT equipment, setting laser power to be 30-50 mu J, and the scanning speed to be 100mm/S, and irradiating a deflection area at fixed points.
  6. 6. The process for machining the through hole with the large depth-to-diameter ratio of the tungsten carbide wedge chopper according to claim 1, wherein in the step S4, the specific steps of electrolytic refining are that a blank body subjected to laser correction is clamped and fixed in electrolytic machining equipment, the axis of the through hole is coaxial with an electrolytic electrode, electrolyte with the same composition in the step S2 is adopted, the electrolyte is regulated to spray at the pressure of 20MPa, and the electrolytic machining equipment is started, so that a recast layer formed by solidifying a hole wall laser machining melt is removed by utilizing an electrochemical polishing effect.
  7. 7. The process for machining the through hole with the large depth-to-diameter ratio of the tungsten carbide wedge chopper according to claim 6, wherein the electrolytic parameters of the electrolytic machining equipment are that the voltage is 8-10V, the current density is 30-40A/dm 2 , and the electrolytic time is 30min.
  8. 8. The process for machining the through hole with the large depth-to-diameter ratio of the tungsten carbide wedge-shaped chopper according to claim 1, wherein after the step S4, the process further comprises the step of ultrasonic cleaning, namely ultrasonic cleaning is carried out on a blank body by using absolute ethyl alcohol, and the cleaning power is 300W for 15 minutes.
  9. 9. The process of processing a through hole with a large depth-to-diameter ratio by a tungsten carbide wedge chopper according to claim 1, wherein in the step S5, the diameter of the diamond microfilament used is 0.16-0.17mm, the particle size of the diamond abrasive particles is 2-3 μm, and a honing machine is started to axially and reciprocally hone the through hole for 3-4 times.
  10. 10. The process for machining the through hole with the large depth-to-diameter ratio of the tungsten carbide wedge-shaped chopper according to claim 1, wherein in the step S6, the specific method for detecting the finished product is that a laser interferometer is adopted to detect the aperture, an atomic force microscope is adopted to detect the roughness and a micro CT is adopted to detect the straightness, the qualification standard is that the aperture tolerance is +/-0.002 mm, the surface roughness Ra is less than or equal to 0.06 mu m, the straightness is less than or equal to 0.025mm, and the qualified finished product is the finished product, otherwise, the process returns to the step S5.

Description

Processing technology of tungsten carbide wedge-shaped riving knife large-depth-diameter ratio through hole Technical Field The invention relates to the technical field of microelectronic tool manufacturing, in particular to a processing technology of a tungsten carbide wedge-shaped riving knife large-depth-diameter-ratio through hole. Background The tungsten carbide hard alloy has excellent properties of high hardness, high wear resistance, high strength and the like, and is a key material for manufacturing the microelectronic packaging wire bonding wedge-shaped riving knife. However, machining through micropores with a depth-to-diameter ratio greater than 100 and extremely high precision on the material remains an important technical bottleneck facing current manufacturing industries. The processing methods commonly used at present all have the following inherent limitations: (1) The micro drill bit adopted in the traditional machining is quick in abrasion and easy to break when the high-hardness tungsten carbide is machined, and the residual broken cutter is difficult to take out and is easy to damage the hole wall. In addition, the machining is easy to generate micro cracks and burrs on the hole wall, and the requirements of the bonding channel on straightness and surface smoothness are difficult to meet. (2) Electric Discharge Machining (EDM) relies on discharging to remove material, and the walls of the holes after machining form recast and microcracks. The tissue is loose and fragile in performance, and is easy to peel off under the high-frequency working condition of the riving knife, so that bonding points are polluted and failure is caused. And when the depth-diameter ratio exceeds 50, dielectric liquid chip removal is difficult, arc discharge and hole type distortion are easy to cause, and the machining precision is out of control. (3) In the laser processing technology, nanosecond/microsecond laser thermal damage is obvious, a heat affected zone is large, a thicker recast layer is easy to form on the hole wall, and molten materials in the deep hole are difficult to discharge, so that the hole channel is easy to be blocked. The femtosecond laser can inhibit a heat affected zone by a cold working mechanism and realize high precision, but the material removal rate is low, the single-hole processing time is too long, the requirement of industrialization on efficiency is difficult to meet, and the economical efficiency is poor. In summary, a single technical route is often subject to thermal damage or chip removal difficulties, or both efficiency and cost. Therefore, high-precision, damage-free and high-consistency processing of micropores with ultra-large depth-to-diameter ratio on tungsten carbide cannot be realized while high efficiency is ensured at present. Disclosure of Invention Aiming at the problems, the invention discloses a processing technology of a large depth-to-diameter ratio through hole of a tungsten carbide wedge-shaped chopper, and the invention discloses a processing technology of the large depth-to-diameter ratio through hole of the tungsten carbide wedge-shaped chopper, which adopts four steps of blank pretreatment, picosecond laser-electrolyte synchronous composite rough processing, laser-electrolytic finishing and diamond microfilament honing finishing, and solves the core problems of melt blockage, heat damage layer, out-of-control precision, low efficiency and the like in the processing of the small hole of the depth-to-diameter ratio. The specific technical scheme is as follows: The processing technology of the tungsten carbide wedge-shaped riving knife large in depth-diameter ratio through hole specifically comprises the following steps: S1, preparing a blank, namely sequentially adopting a vacuum powder mixing, cold isostatic pressing and vacuum sintering process to prepare a tungsten carbide hard alloy blank with high compactness and uniform components; S2, compound rough machining, namely clamping the blank body on a rotatable clamp, enabling the axis of the blank body to be coaxial with a laser light path, adopting an infrared skin second laser to align a designated machining area to etch away materials, machining in a layered spiral feeding mode to form a through hole, and synchronously spraying electrolyte to the machining area while laser machining, wherein the electrolyte is subjected to chemical reaction with a melt generated by the action of laser and is removed; s3, laser correction, namely detecting the deflection data of the pre-through hole by using a micro CT device, accurately transferring the blank to a laser correction device, and carrying out fixed point correction on the deflection area of the through hole by adopting low-power laser according to the detection data; S4, electrolytic finishing, namely polishing the inner wall of the through hole in an electrolytic machining mode to remove melt remained by laser machining; S5, honing finishing, namely cla